Re: overall performance

[Mats Bengtsson]

Comparing to the -O flags of most compilers, to optimize the generated code
at the expense of longer compilation time, I see both similarities and
differences:
- It's something you turn on when you know that you input source code is
 more or less correct.
- Most users don't know and don't care exactly what extra optimization 
is done.
 (Even if a compiler often has many different levels of optimization 
available
 and a list in the documentation of what each level does, I'm sure that 
almost
 all users choose the highest level of optimization for production code.)
* If the compiler is bug free, the resulting program should be equivalent
  no matter if you use -O or not. However, in the case of LilyPond, the
 semantics of the music will be the same, but not the layout.
* In the case of LilyPond, this is something you turn on before doing the
 final tweaks of the layout, which means that the turn-around time for the
 fine tuning part of the typesetting will be affected by the longer 
compilation
 time.

  /Mats

Graham Percival wrote:
> > > Would it be desirable to have
> > > \fastProcessing
> > > \qualityProcessing
> > > macros?
> >
> > No, this is as stupid as the 'windows video acceleration' settings:
> > most users won't know they're there,
>
> Well, that's what the documentation is for.
>
> > and if they know, it's not clear what the settings do.
>
> That's what ly/property-init.ly is for.
>
>
> We occasionally get people (even me!) sending "bug" reports about
> \override Score.PaperColumn #'keep-inside-line = ##t
>
> You said that it added 5% or 10% to the processing time, so it wasn't 
> worth having it on by default.  That's fine; I'm not criticizing that 
> decision.  But what if somebody _is_ willing to spend that extra 
> processing time to get great-looking music?  Currently they need to 
> comb through the manual (and program reference, because I haven't 
> documented every case because I don't know them all!) to find all such 
> options.
>
> At the very least we should have a doc page with the "higher quality 
> output commands that are turned off by default" \override commands.  
> Why not also make a
> \qualifyProcessing
>
> macro that sets it up for them as well?
>
> Cheers,
> - Graham
>
>
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--
=============================================
        Mats Bengtsson
        Signal Processing
        Signals, Sensors and Systems
        Royal Institute of Technology
        SE-100 44  STOCKHOLM
        Sweden
        Phone: (+46) 8 790 8463                         
       Fax:   (+46) 8 790 7260
        Email: address@hidden
        WWW: http://www.s3.kth.se/~mabe
=============================================